Generator for high-frequency currents.



P. o. PEDERSEN. GENERATOR FOR HIGH FREQUENCY CURRENTS.

APPLICATION FILED MAR. 24, 1913.

D Patented June 26, 1917.

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PEDER OLUE' -PEDERSEN,' OF FREDERIKSfiERG, DENMARK, ASSIGNOR 'IO FEDERAL TELEGRAPH COMPANY,A CORPORATION OF CALIFORNIA.

GENERATOR FOR HIGH-FREQUENCY connnn'rs.

, Specification of Letters Patent.

Patented June 26, 191W.

1 Application filed March'24, 1913. Serial No. 756,323.

' To all wiiom it may concern Be it known that I, 'PEDE'R'O-LUF Penna-- SEN, a subjectof' the King ofDemnark, re-

siding at Frederiksberg, near Copenhagen,

and Kingdom OfDemnark, haveinvented 'certain new and useful Improvements in' Generators for High-Frequency Currents, of which the following is a full, clear, and exact'description. Q Y v I This inventionrelates to generators for high frequency currents.

It has been heretofore proposed to produce currents of high frequency by feeding direct current to an oscillatory circuit including .a self-induction L, a condenser C, and an arc, the period of the alternating I current being equal to 21r /L in accordance with Kelvins formula. v when this method has been used even where However,

the are has been arranged in an atmosphere containing hydrogen and the anode of the are cooled, the maximumfrequency which can be obtained is limited, since it is essential that the anode be cooled to prevent the current passing through the circuit from becoming amere direct'current. It is obvious that such cooling of the anode will necessarily limit the frequency which can be obtained,

The object of my inventlon is to provide a generator with which frequencies, higher I the than those previously obtained, can be procured, andwith this object in view, the invention contemplates the provision of a plurality of arcs which are so arranged that currentimpulses pass successively throughthe arcs, as for example, where three arcs are used only each third current impulse passes, through a single arc, and this are thereafter remains extinguished for two entire periods which gives the are a sufficiently long time for being cooled. If

the shiftings of the are are promptly timed, this will not affect the period of the alternating currents which passes through the circuit containing the induction L and the condenser C. Instead of changing the are through which the current passes for each current impulse it is suflicientif the arc,

through which the current passes, is changed after the second, third, etc., current impulse. However in the preferred embodiment of the invention,'it is preferable to shift the are after each period. The period for shifting the arcs need not be in strict accordance with the natural period 21r /LU of the oscillatory circuit. The period of the alternating current is, of course, determined by the period of the shifting of the arc.

- One of the important advantages of the present system is that it provides a sufliciently longtime for each arc to cool and deionize, that no special methods for cooling the are need be utilized. It is also obvious that the discharge completely .loses I the character of an arc since so long a time elapses between the passage of single cur- In this manner, the same anode may be used for a plurality of discharge spaces.

The invention and its object will be apparent from the embodiments of the 'invention shown in the drawing, wherein Fi ures 1 to 5, inclusive, show various modi cations of the circuit. arrangements which may be used, but it is intended that such modifications and embodiments will be regarded as descriptive and not as limiting the invention.

' An example .of the use of two arcs or discharge spaces a and b is shown in Fig. 1. Between the cathodes and the feed conductor .are inserted self inductions La and Lb If first a current impulse passes through the discharge space a, a' free oscillation is thereby induced in the circuit 1; a period later the oscillation in this circuit 7 will small as possible.

somewhat different arrangement is shown in Fig. 2. The distributing circuit is here substituted by two coils La and L b coupled to the coils'L'a and Lb respectively; through the two first named coils is passed an alternating current from a generator '0;

i the period of the alternating current is 2T.

The manner of acting will easily be understood; each second discharge passes through the discharge space a, each second throiwh the discharge space I). If the period of t e alternating currents is-4T, two discharges will pass through the discharge space a, thereafter two discharges through the discharge space b. and so on. Analogical methods can be used at three and more discharge spaces.

Fig. 3 again shows another arrangement. Here Sn and S7) designate interrupters which alternately close and interrupt the connection between the cathodes and the feed conductor. The contact period ought to be in the neighborhood of the period T of the oscillation circuit, or in the neighbor-' hood of WT, where n is an integer. In the latter case first n discharges are passing through the discharge space a, thereafter 'n discharges through the discharge space I), and so on. For sake of simplicity, in the following a is presumed to be equal to Z.

If the duration of the contact, the length of spark, the feed tension and feed current and the values of the resistance R, the induct-ance L and the capacity C be suitably chosen, it can be obtained that the inter-Z rupters Saand S?) work completely without sparks. If at same time the sparking distances a and b are chosen in such a manner,

that the potential between the electrodes during the passage of the current is small, while the ignition tension is relatively high, a very high efliciency is obtained, pretty near all the energy of the direct current being transformed into oscillations. It is'a matter of course, that also at this arrangemenlt three or more discharge spaces can be use Fig. 4 shows the corresponding arrangement for two discharge spaces in series. Tlggdmanner of acting will easily be underst Fig. 5 shows a somewhat different ar-- a manner, that the peri0d-for the two circuits consisting of the discharge space a,

the inductance La and the capacity Ca, and the discharge space 6, the inductance L7) and the capacitylOb, respectively, is

muchless than T.

The discharges are incurredby in the inductances La and L6 sudden high tensions being alternately induced which cause sparks to jump'through the discharge-space a and the discharge space 5, respectively and thereby starts the discharges proper.

The starting sparks follow each other with an interval of about 'nT. whereT as usual indicates the natural period of the oscillation circuit. Also att-his arrangement the number of discharge spaces is arbitrary.

Having now particularly described and ascertained the nature of my said invention and in'what manner the same is to be performed. I declare that what I claim is 1. A generator for high frequency currents comprising a single oscillation circuit having a plurality of discharge spaces therein, and means for directing a high frequency currentthrough said oscillation circuit and for successively and periodically directing said current through said spaces at periods which are a simple multiple of the high frequency current lation. circuit. I

2. A generator for high frequency currents comprising 'a single oscillating circuit having a plurality of discharge spaces connected in parallel therein. and means for directing a high frequency current through said oscillation circuit and for successively and periodically directing said current through said spaces. at periods which are a simple multiple of the high frequency current passing through the oscillation circuit.

Inwitness whereof. I have subscribed my signature. in the presence of two witpassing through the oscil: 

